A system for assisting in assessing a state of a subject's lung is, for instance, an absorption computed tomography imaging system. An absorption computed tomography imaging system comprises an x-ray source and an x-ray detector, which are rotatable around a subject's lung to be imaged such that x-rays generated by the x-ray source traverse the lung in different directions. The x-ray detector detects the x-rays after having traversed the lung and generates projection data based on the detected x-rays, wherein a reconstruction unit reconstructs an absorption computed tomography image based on the generated projection data.
In the absorption computed tomography image air-soft tissue interfaces are not very well detectable, thereby reducing the usability of the absorption computed tomography image for assisting in assessing a state of a subject's lung.